Hey.. First of all I think its importent for you to realize what det problem actually is here. You gotta find out what the cause is..
Mayb ur just psysically tired.. like me.. it helps a lot if you find some time to exersize in ur sparetime.
If its mentally ... I think you shud talk with sumbody bout' it.
I think its easier to be sad and not to do anything. But the thing is that it is only our own faulth if we feel that way. Why not be happy and satisfied with everything you DO have in life instead of focusing on all the difficulties in life? Its easy to say so, but not that easy when you have to take action and make changes in life.
I dont know if you gained anythin' of me sayin all this , but atleast I tried he he..